I started my 155V6 this dinner and was greeted with a very loud, and embarrasing metallic rattling noise. Trying to be cool, hmmmmm.. i drove off ignoring it. About 100 yards down the road it stopped, 'great I thought. I then stopped at some traffic lights and noticed a slight 'whiney' type noise (hard to describe) it seems that it dissapears at idle and doesn't get progressively louder with increased revs! Any ideas?